The fully automatic screen printing process involves many steps, and screen cleaning and decontamination after screen printing are also very important. However, seemingly simple operations also cause waste due to improper handling, which not only affects print quality but also shortens the life of the screen. So how much do you know about screen cleaning for fully automatic screen printing?

1, Dust and dry ink in printing part

When we find dust or dry ink in the printing section, we need to remove the dust from the screen. At this point, we should stop the printer and lift the screen frame. However, we have found that some operators often wipe the bottom of the screen with a hard cloth soaked in solvent, often damaging the screen. In fact, a professional operator rarely touches the printing surface of the stencil because he knows that the sharpness of the printed graphics requires that all graphic edges maintain a clear emulsion graphical interface. Hard friction will damage the graphic interface of the emulsion layer, and even wipe off the emulsion layer, leaving only the exposed mesh. When printing high-mesh color images, the emulsified film under the silk is only 5-6 μm thick, and the wire diameter of the silk screen itself may only be 30 μm, which cannot withstand hard friction. Therefore, the key to avoiding coarse decontamination is to prevent the filter screen from being contaminated first.

2, Screen pollution

The main reason for screen pollution is improper ink control, which keeps dry ink in screen. When using solvent-based ink or water-based ink, the reason is that the ink is diluted or too thick. When mixing inks, add additives in the prescribed amount. In addition, a small amount of preset ink is often added in printing production to keep the state of the ink unchanged. When using UV-curable inks, you should try to avoid exposing your screen to UV light and sunlight. Another ink control problem is related to improper printing speed control. Improper speed control of automatic or manual printing presses can lead to uneven supply and cause the ink-deficient screen to dry quickly.

3.Ink drying

The last cause of ink drying is improper adjustment or wear of the blade. When printing an image of a fine layer with a high mesh number, it is necessary to use a blade having sharp edges, and the horizontal angle is about 75 degrees. Since the scraper is deformed or worn during normal use, the sharpness of the peripheral image is reduced, which indicates that the ink may not pass through the grid properly. If this problem is not resolved in time, the ink will dry on the Internet. In order to avoid the above problems, the squeegee should be turned regularly to extend the life of the squeegee edge, or use a new squeegee before the quality of the printed graphics does not decrease.

Finally, in order to make the mesh function properly, we should also pay attention to cleaning the dirt on the ink or substrate. Due to the electrostatic adsorption of pollutants in the air and poor storage conditions, the surface of printing materials will be soiled by dirt. The above problems can be solved by improving storage conditions and process control. In addition, the use of static eliminators and printing material decontamination devices can also prevent dust and dirt from being transferred from the surface of the printing material to the web.